In many injection molding apparatuses, a valve pin is used to open and close a gate into a mold cavity in order to control the melt flow into the mold cavity. Depending on the layout constraints in the injection molding apparatus, it can be desirable to provide an actuating mechanism for the valve pin, that extends laterally to the valve pin.
The technical literature shows several hot runner injection nozzle designs having a valve pin actuating mechanism incorporating a rocker arm or a linkage that extends laterally either to engage the valve pin directly, or to engage a guide element, which retains the valve pin. In some configurations the rocker arm engages the valve pin or the guide element opposing jaws, (eg. upper and lower jaws) that capture the valve pin or the guide element. The rocker arm is connected at its rear end to an actuator, such as a pneumatic cylinder, which controls the movement of the rocker arm, and in turn, the movement direction of movement of the valve pin.
During use of such mechanisms however, it can occur that the mechanisms wear or fail where the jaws engage the valve pin or the guide element. There is a continuing need for an improved, laterally actuated valve gating mechanism.